(1) Field of the Invention
This invention relates to the application of chemical treatments to cotton and cotton-containing fabrics to impart smolder resistance to the products made therefrom. The method of this invention is of particular significance to the users of upholsterytype, heavy weight fabrics, and is considered a substantial improvement over the known smolder-retardant finishes.
(2) Description of the Prior Art
It is known that cellulosic fabrics are highly susceptible to cigarette ignition, a smoldering-type reaction. It is also known that the mechanism of flame retardance and smolder resistance are decidedly different, so much so that flame retardant fabrics generally contribute to smoldering hazard associated with textiles.
The smoldering characteristics and imparting smolder-resistance to cotton-containing fabrics have been studied very little. Backcoating with a latex or treatment with sulfur, or with boric acid, have been mentioned in the literature as methods for imparting smolder resistance to cotton-containing fabrics.
Nestor Knoepfler et al disclose in U.S. Pat. No. 4,012,507 a vapor-phase boric acid treatment for application to cotton batting. Special equipment and techniques must be employed in that process, thus making it unattractive for its use with heavyweight upholstery textiles.
Chemcial Abstracts (C.A. 89, 76594e), indicates that McCarter in patent application Ser. No. 870,385 now abandoned discloses the use of sulfur as a smolder inhibiting agent for cellulosic insulations. The method of application indicated by that disclosure indicates that it is not practical for fabrics. Sulfur requires relatively large amounts of deposition on the substrate to be capable of imparting smolder resistance. Results obtained in the deposition on heavyweight fabrics have been erratic. The resulting fabrics are quickly associated with the obnoxious odor of sulfur.
Backcoating as a method of imparting smolder resistance is objectionable because the coatings impair the aesthetic properties of certain fabrics, essentially heavyweight fabrics, and therefore backcoatings do not lend themselves to applications to all types of cotton-containing fabrics.
Dusting and hot aqueous treatments have been mentioned as smolder-resistant process for cellulosic materials. The dusting of boric acid as applied to batting is not feasible for textiles. The hot aqueous treatment requires energy to be supplied to the solution at all times, thus making the system unattractive. Also, such a system is not ameanable for use on low wet pickup finishing equipment. Also, the availability of boric acid is limited thereby making the treatment economically impractical.